Inkjet printers have one or more printheads that eject drops of liquid material, referred to generally as ink, onto a substrate or previously ejected drops of material. Each printhead includes a plurality of inkjets typically arranged in an array. Each inkjet has a nozzle that communicates with an opening in a faceplate of the printhead to enable one or more drops of material to be ejected from the inkjet and through the opening with which the inkjet nozzle communicates in the faceplate. The inkjets can be implemented with a variety of different configurations known to those skilled in the art. Some well-known configurations use piezoelectric and thermal ejectors in the inkjets.
Some of the ink ejected from the inkjets adheres to the faceplate and can collect dust and other debris. If the ink and debris are not removed from the faceplate, then the residual ink and debris may block one or more openings in the faceplate. Printhead cleaning is typically performed within a maintenance station mounted within the printer chassis so the printhead and maintenance station can be moved relative to one another for cleaning. In some maintenance stations, an applicator wipes the faceplates of the printheads with a non-volatile solvent to liquefy the residual ink. Then, a pair of wipers move across the faceplates. The first wiper helps spread the solvent over the faceplate and loosen the debris from the faceplate. The second wiper separates the residual ink and the debris from the faceplate and moves the residual ink, debris, and solvent into a waste receptacle.
These maintenance stations, however, suffer from a number of limitations. For one, they require a supply of non-volatile solvent and an applicator to wipe the faceplate with the solvent. The applicator and the solvent add expense to the printer. Additionally, an actuator and mechanical linkage are needed to move the applicator. Another limitation is the need to have a pair of wipers, each of which provides a different function. Thus, one wiper may wear at a faster rate. To simplify repair of the maintenance station, when one wiper requires replacement, both wipers are replaced. Thus, a portion of the life of one wiper is wasted and the expense of maintaining the printer is increased.
Another type of printhead wiping system is disclosed in U.S. Pat. No. 8,591,001. This system includes a pair of wipers that are operated to clean different portions of the same printhead. One wiper is raised to engage a faceplate of a printhead at a first location and then the wiper is moved across a portion of the printhead to wipe a portion of the nozzle openings in the faceplate. The wiper is then moved out of engagement with the faceplate and the other wiper is raised into engagement with the faceplate at a second location. The other wiper is then moved across another portion of the printhead to wipe another portion of the nozzle openings in the faceplate. This wiper is then lowered and the printhead is returned to normal printing operations. The limitations of this type of printhead wiping system include difficulty in adjusting the position of the wiper ends as the wipers wear, the difficulty in holding the wiper adjustments, and the complicated manner of mounting the wipers to support members in the wiping system.
What is needed is a maintenance station that enables efficient cleaning of printheads in an inkjet printer without requiring solvent application or complicated mounting of the wipers in the cleaning system.